Slack adjuster



Aug; 5, 1930.

H. E. ANDERSON SLACK ADJUSTER Filed June 2 4, 1950 4 Sheds-Shed 1 17 NTQR" man/Q v ATTORNEY Aug; 5, 1,930. I E. ANDERSON SLACK ADJUSTER I Filed'June 24 1930 lsheets-sheeti 2 INVENTOR IQEL/ZD 4 ATTORN EY 1 930. H., E. ANDERSON 1,772,435.

- SLACK ADJUSTER Filed June 24, 930 4 Sheets-Sfieet 5 TTORNEY v 7 Afig. 5, 1930. H. E. ANDERSON SLACK ADJUSTER Filed June 24, 1930 4 Sheets-Sheet A MMWJMM Q VINVENTOR ji 2 C0 WTTOQQE Patented Aug. 5, 1930 I "U IT-ED ST -T ss ATENT orrlcE HARLEY, E. ANDERSON, or KANs s CITY, MIssoURi, AssIGNoR TO-GUSTIN-BACON MANUFACTURING 00., or KANSAS CI Y, MISSOURI, AooRroRA'rIoN or: MISSOURI SLACK AnJns'rER Application filed June 24,

5 I am familiar, are subject to the objection that when it becomes necessary to replace the brakeshoes with new ones, due to the old ones-being worn out, the dogs whichengage the rack must be pulled downwardly until they clear 1 0 the rack, and held there while the rack bar.

is being pushed back, as the strain was on the rack and dogs. 1

My invention has for its principal object, to provide a'constructio'n which will permit the workmanto turn therack bar a' quarter turn, which rotation will retract the dogs by compressing the two springs under the dogs,

and the rack bar can be freely drawn back the required distance. I also provide a construe tion which will make it impossible to reconnect the top rod to the 'truck'lever until the rack bar is returned to its normal position, in which the dogs will be in engagement with the teeth of therack bar. j v

A further object is, to construct the device so that the rack will be undergcompressiom In the old type it was under tension, and as a consequence, when. the brakes were applied any internal weakness in the rack, such as o flaws, etc., would cause the rack to break or pull in two, and thus bring about a failure of the brakes. In my improved construction,

.. such an event cannotoccur, as the rack is never sub ect to tenslon.

vide for closer connection to the cylinder lever, thus bringing the top rod more nearly in a horizontal line, which is most desirable in avdevice of this type. I

A further object of my invention is, to, shorten the overall length of the rack by reducing the overhang, and extending the top rod through the rack. v I A concrete embodiment of my invention is illustrated in the accompanying drawings, to be considered as part of this specification, in which v Fi 1 is a phantom top plan view through the oor of a freight car, showing my improved slack adjuster;

A further object of my invention is, to pro- A nut 13 is then screwed tightly on to the top 1930. Serial 1%.;4'63 74.

,Fig. 2is a side view of the device as shown 1n Fig. 1, partly in section, showing'the position of the device when the brakes are in ref leased position; v

Fig. 3 is a detail View, showing the position of the device when the brakes are. set, with no wear on thebrake shoes;

Fig. 4 isa similar View, showing the posi-- tion of the device with the'brakes set, where i the brake shoes onthe wheels have partially '60 worn off a'ndthe devicehas taken up theslack; a it Fig. '5 is a view similar, to Fig. 4:, showing the device being compensated for the' wear on the brake shoes; 1

Fig. 6 is an enlarged fragmentary top plan View; 1 3

' Fig. 7 is the same in side elevation;

Fig. 8 is a side View of the device as shown in Fig. 6, with the slack ;.adjuster shown in section and o Fig. 9 is a sectional view, taken on line 99 inFig.8.

Similar reference numerals refer to similar parts throughout the entiredescriptionL As shown in the drawings, the brake .cyl-

' inder 1 is connected to links 2, which in turn are connected to the [cylinder levers 3 and 4.

- As the construction is duplicated for each end of'th'e car, I shall confine my description to the device in connection with only one end of the car. j i

The vertical truck lever 5 is connected to the brake jaw- 6 on the end of the top rod 7, by means of the brake pin 8'. The other end of the top rod 7 is provided with threads 9, which fit internal threads cut in the rack cast-- ing'lO. This rack casting 10, as clearly seen in the cross-section Fig. 9, is round, and has a plurality of teeth 11 formed on 'a portion of itsperiphery. An opening 12 extends longitudinally of the rack casting 10. The top rod 7 extends through this opening 12, and is screwed into threads in the rack casting 10.

rod 7, and its end l iispeened or riveted over, thus effectually preventing the loosening of the nut 13.

-A rib 15, which serves as a detent, is cast or formed on the exterior surface of the rack 10! Ill) casting 10, and extends for the full length which I mount adpg 19, one end'20 of which engages teeth 11 ofthe. rack 10. vA coil spring 21 serves to hold the dog 19 normally project.

ed from the cylindrical recess'18 in which-it is mounted, and in engagement with the rack.

teeth 11.

A chamber 22 is formed in the portion 17 in which I mount a coil' spring 23, which extends into an extension 24, formed on whatI term a cross head 25. This cross head 25 also has a vertical cylindrical recess 26, in which I mount a dog 27, which corresponds in all respects to the dog 19, a coilspring 28 serving to hold it in engagement with the teeth llot' the rack casting 10.. To prevent the rack casting 10 sliding out of the housing 16, I form a stop or collar 36 on the end of the rack casting 10, which may be cast integral therewith, or secured in position by a set screw, or by any other convenient form for fastening a stop collar. The housing 16 has an upper portion 29, into which the end of the cylinder lever 3 extends, and which is pivotally secured to the housing 16 by meansof a special brake pin 30, which is formed without a head, thus bring-' in the cylinder lever-3 closer to the top rod 7 tian would otherwise be possible. The-pin 30 is prevented from working out, by means of a cotter pin 31, mounted in the wall of the housing 16.

A permanent stop 32 is suitably securedto the car, for the cross head 25 to abut in the manner hereinafter set forth. The housing 16 has-as an arcuate slot 33 formed in one of its side walls, in which is located. the rib 15, which abuts the shoulders 3%1and 35 at the ends of said slot 33. A similar slot is formed in the wall of the cross head 25.

The. operation of the device is as follows:, The air being admitted'into the cylinder 1,- its piston shifts the links 2 and in turn the cylinder lever 3. This moves the top red 7, and consequently the vertical truck live lever 5, and the brakes are applied. My. device is set so that with a movement of the air piston ofnot less than seven nor more than nine inches, as is required, the cross head 25 will abut the permanent stop 32. If the brake shoes wear, the top rod 7 will attempt to carry the housing 16 farther; this being-prevented by the stop 32, the spring 20 will be compressed, and the dog 27 will be advanced a distance suflicient to take up the slack. As the brakes are released, the spring 20 will expand and advance the housing 16, until the dog 19 engages the correct tooth 11 on the rack 10. The collar 36, abutting the housing 16, prevents the rack casting 10, from sliding out of the housing 16. In this manner, the device automatically takes up the slack, maintaining at. all times the same amount of air piston travel, thus holding the cylinder levers 3 and 4 at approximate right angles to the center line of the air cylinder 1, which is the ideal operating condition.

' When the brake shoes are worn out, and it becomes necessary to apply new shoes, the car repairer first'pulls the pin 8-, which connects.

" meet the lever 5since it has been automatically shortened by my device taking up the slack produced by the wearingof the shoes. He then turns the top rod 7 by hand, which carries with it the rack 10, being secured thereto by the threads 9 and the nut 13. This rotation compresses the dogs 19 and 27, and

inside the cross head 25 and the dogs 19 and 27 could not mesh with the teeth 11 of the rack 10; this could not be seen or noted until attention was drawn thereto by failure of the device to function. The connection between rod 7 and lever 5 cannot be made, because the workman has rotated the .rod 7 a quarter of a revolution and the jaws 6 no longer register with the lever 5, so he must turn the rod 7 back in order to insert the pin 8. By so doing, the rack 10 is automatically reset so that the dogs 19 and 27 will again engage the teeth 11 of the rack 10, and the device is again ready for operation.

The rib or detent 15 and the shoulders 34; and 35 are provided, so the workman can not continue to rotate the top rod 7 until the 't-eethll of rack 10 are on top and the dogs 18 and 2.7 underneath, as the device would then .be inoperative. But with the rib 1'5 and shoulders 34 and 35 constructed as described, he must turn the rod '7 back to the position in which it was when he disconnected it, which resets the rack 10 in the proper operative position. In fact, unless he does this, he can not possibly connect the rod 7 to the lever 5; and; the provision of the collar 36 permits necessary adjustment of the device without risk of pulling the rack 10 entirely out of the housing 16. By locating the cylinder lever 3 at the top of the housing 16, it is apparent I. shorten the over-all length of the device and gain considerable more take-up, without any increase of the overhang of the rack 10.

Having described my invention, what I rel l O "tance, and means to gard as new, and desire to secure by Letters Patent of the United States, is: g 1. In an'automatic slack adjuster, around sleeve, teeth out on the outside thereof, dogs which engage said teeth, said sleeve being capable of rotation for a predetermined'disprevent its rotation beyond said point.

2. In an automatic slack, adjuster, a roundsleeve, teeth out on the outside thereof, spring-pressed dogswhich' engage said teeth,

said sleeve being capable of rotation for a predetermineddistance, and means to pre vent its rotation beyond said, point. v

, 3. In an automatic slack adjuster, a round sleeve, teeth out on the outside thereof, a housing in which said sleeve slides, said hous-, ing having downwardly.dependingand up-' wardly extending portions, a cross head, an

.cxtension'thereon'Whichslides into a chamber in said downwardly depending portion,

a spring which holdssai'd extension normally projected therefrom, a dog mounted in saidhousing, a springto hold said dog in engagement with the teeth on said sleeve, a-

similar dog and spring in, said cross head, said sleeve. loeing secured to the top rod of analr brake rigging, a longitudinal rib on said sleeve located in an arcuate slot in said housing, the ends of which limitthe, rotation of said sleeve,'means to connect the upwardly extending portion of the housing to the cylinder lever of an air brake, and a permanent stop which said cross head abuts.

4:. The combinatiom'with an air brake rigging, of a round sleeve, through which the I s top rod of the brake rigging extends," threads on said rod which fit'threads in said sleeve, a

nut to secure said rodand said sleeve together, teeth cut on the outside of said sleeve, a housing in which sald sleeve sl des, a dog in said housing which engages said teeth, a cross head slidably connected to said housing, a dog in said cross head which engages said teeth, said sleeve'beingcapableof rotation for a predetermined distance, and means to preprising a housing, a cross head,ja rackfdogs which engage said rack, springs which hold said dogs normally in said. engagement, in arrangement so that the rotation of said rack will compress said springs and disengage said dogs, means to limit the amount of said rota tion', means to connect the cylinder lever to said pin in place.

the top of said housing, and means to prevent said-last named means being disconnected.

7. An automatic slack adjuster, connected to the top rod of an; air brake rigging, comprising a housing, a cross head, a rack, ogs

which engage said rack, springs which hold said dogs normally in said engagement,'in

arrangement so that the rotation of said rack will compress said springs and disenga e said dogs, means to limit the amount of sai rotation, apin Which'connects the cylinder lever to the top of said housing, and means to hold 8 An automatic slack adjuster, connected to the top rod of an air brake rigging, comprising a housing, a cross he'ad slidably engaged therewith, a spring to hold said cross head normally projected 'from said housing,

a rack fixedly secured to said top rod, dogs which engage said rack, springs which hold 'said dogs normally in said engagement, in

arrangement so that the rotation of said rack will compress said springs and disengage said dogs, means'to limit the amount of said rotation, and a stop on said rack which abuts said cross head. I

9. The combination, with an air brake rigging, of a' round'sleeve, through which the top rod of the air brake rigging extends, means to fixedly secure said rod to said sleeve,

teeth out on the outside of said sleeve, a hous ing-inwhich said sleeve sli'des,-a dog in said housing which engages said teeth, across head slidably connected to said housing, a dog'in said cross headwhich engages said teeth, said sleeve being capable of rotation -adistance sufiicient to disengage said dogs from said teeth, and means to prevent such rotation beyond said point.

10. The combination, with an air brake rigr ging, of a round sleeve,- through which the top red of the brake riggin extends, threads on said rod which fit thrca s in said sleeve, a

nut to secure said rod and said sleeve together, teeth out on the outside of said sleeve, a, housing in which said sleeve slides, a dog in saidhousing which engages said teeth, a cross head slidably connected to said housing, a

spring to hold said cross head normally projected from said housing, a dog in said cross head which engages said teeth, said-sleeve'being capable of rotation a distance suflicient to disengage said dogs from said teeth, and

means tp prevent such rotation beyond said point.

' 11. riggin The combination, with an air brake of a round'sleeve, through which the top rodof the brakerigging extends, means to fixedly secure said rod to said sleeve, teeth cut-on the outside of said sleeve, a housing in which said sleeve slides, a dog in said housing which engages said teeth, a cross head slidably connected to said housing, a spring to hold said cross head normally projected from said housing, a dogin said cross head which en ages said teeth, said sleeve being capable o rotation a distance su'fiicient to disengage said dogs from said teeth, and means to prevent such rotation beyond said point.

.12. An automatic slack adjuster, connected to the top rod of an air brake rigging, comprising a housing, a cross head, a rack,'dogs which engage said rack, in arrangement so that the rotation of said rack will disengage said dogs, and means to limit the amount of said rotation.

13'. An automatic slack adjuster connected to the top rod of an air brake rigging, comprising a housing, a cross-head, a rack,'dogs 5 whichengage said rack, springs which hold said dogs normally in engagement in arrangement so that the rotation of said rack will compress said springs and disengage said dogs, means to limit the amount'of such rotav tiodandineansto prevent-the longitudinal movement of the rack in said housing beyond the predetermined point.

14. An automatic slack adjuster, connected to the top rod of an air brake rigging, comprising a housing, a cross head, a rack, dogs which engage said rack, in arrangement so that the rotation of said rack will disengage said dogs, means to limit the amount of said rotation and meansto prevent the longitudinal movement of the rack in said housing beyond the predetermined point.

' 'HARLEY E. ANDERSON. 

